In the current state of the art different exhaust gas recirculation systems in internal combustion engines, called EGR systems, are known.
These systems recirculate exhaust gases from the exhaust manifold to the intake manifold of the engine after subjecting them to a cooling process for the purpose of reducing the amount of NOx emissions.
As the cooling of the exhaust gases is not appropriate in certain operating conditions of the engine, the use of by-pass pipes has been proposed in the art, allowing the recirculation of exhaust gases without passing through the heat exchanger under the control of a valve channeling the exhaust gases either towards the heat exchanger or else towards said by-pass pipe, according to pre-established conditions.
Different proposals for inlet valves for heat exchangers with by-pass pipes are known, such as those disclosed in patent EP 0971 427 B1 and in patent applications WO 03/085252 A2, WO 03/062625 A1, EP 1 291 509 A2 and EP 1 355 058 A2, which have several drawbacks which the present invention aims to solve.